This castle is definitely worth visiting. The history alone is amazing. The full history is here: http://www.1000islands.com/alexbay/boldtcas.htm

In short, Boldt Castle was built at the turn of the century by multi-millionaire George C. Boldt for his wife, Louise, as a testimony his love for her. However, this love story turns tragic when his wife passed away (there are rumours that she left him too). The castle was left unfinished because for whatever reason he dropped all work immediatly. The castle suffered vandalims and damage for years. However, it is now under restoration and is looking good. The cost of visiting the castle goes towards restoration. The plan is to make it what it was once meant to be! I have two relatives who work at this castle and both agree it’s haunted! Some very strange things have happened there. Definitely worth the visit and you can take in a tour of the 1,000 islands and hear all the history involved with that (bootleggers, love stories, etc).